Characterization of a discontinuous epitope of the HIV envelope protein gp120 recognized by a human monoclonal antibody using chemical modification and mass spectrometric analysis.
Characterization of a discontinuous epitope of the HIV envelope protein gp120 recognized by a human monoclonal antibody using chemical modification and mass spectrometric analysis.
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使用化学修饰和质谱分析对人单克隆抗体识别的 HIV 包膜蛋白 gp120 的不连续表位进行表征。
DOI：
10.1016/j.jasms.2010.03.031
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发表时间：
2010
影响因子：
3.2
通讯作者：
Tomer,KennethB
中科院分区：
文献类型：
--
作者：
Hager-Braun,Christine;Hochleitner,ElisabethO;Gorny,MiroslawK;Zolla-Pazner,Susan;Bienstock,RachelleJ;Tomer,KennethB
中和性抗HIV抗体的一个子集识别人免疫缺陷病毒包膜蛋白gp 120上的表位。当gp 120与其主要受体CD 4结合时，这些表位在构象变化期间暴露。基于赖氨酸和精氨酸残基的化学修饰，然后通过质谱分析，我们确定了由人单克隆抗体559/64-D识别的gp 120上的表位，该表位先前被发现对CD 4结合结构域具有特异性。重组全长糖基化gp 120中的24个赖氨酸和精氨酸残基进行了表征; 2个赖氨酸残基和5个精氨酸残基的相对反应性受559/64-D结合的影响。数据显示表位是不连续的，并且位于CD 4结合位点附近。此外，位于二级受体结合区的残基和远离CD 4结合位点的几个残基的反应性也被Ab结合改变。这些数据表明，559/64-D的结合诱导的构象变化，导致改变的表面暴露的特定氨基酸远离CD 4结合位点。因此，559/64-D与gp 120的结合不仅影响被识别为表位的CD 4结合位点，而且似乎对全长糖基化gp 120的表面暴露残基具有全局影响。
A subset of the neutralizing anti-HIV antibodies recognize epitopes on the envelope protein gp120 of the human immunodeficiency virus. These epitopes are exposed during conformational changes when gp120 binds to its primary receptor CD4. Based on chemical modification of lysine and arginine residues followed by mass spectrometric analysis, we determined the epitope on gp120 recognized by the human monoclonal antibody 559/64-D, which was previously found to be specific for the CD4 binding domain. Twenty-four lysine and arginine residues in recombinant full-length glycosylated gp120 were characterized; the relative reactivities of two lysine residues and five arginine residues were affected by the binding of 559/64-D. The data show that the epitope is discontinuous and is located in the proximity of the CD4-binding site. Additionally, the reactivities of a residue that is located in the secondary receptor binding region and several residues distant from the CD4 binding site were also altered by Ab binding. These data suggest that binding of 559/64-D induced conformational changes which result in altered surface exposure of specific amino acids distant from the CD4-binding site. Consequently, binding of 559/64-D to gp120 affects not only the CD4-binding site, which is recognized as the epitope, but appears to have a global effect on surface exposed residues of the full-length glycosylated gp120.